1. Field of the Invention
The present invention relates to a circuit breaker having an operating mechanism with a solenoid actuated trip device and close device and, more specifically, to solenoids coupled to their respective devices by an ultra-lightweight member.
2. Background Information
Electrical switching apparatus for opening and closing electric power circuits typically utilize an energy storage device in the form of one or more large springs to open and close the contacts of the device. Such electrical switching apparatus includes power circuit breakers and network protectors, and electric switches which are used to energize and deenergize parts of the circuit or to transfer between alternative power sources. These devices will be identified jointly by the phrase “circuit breaker” hereinafter. The circuit breaker includes an operating mechanism and a control system. The operating mechanism further includes a trip device and a close device. The trip device has an open spring, or springs, which rapidly separate the contacts to interrupt current flowing in the power circuit. The close device has one or more large springs to close the contacts of the device into the large currents which can be drawn in such circuits. The control system is structured to provide instruction to the trip device and the close device.
One known system for actuating the trip device and the close device included a linear solenoid 1 having a plunger 2, as shown in FIG. 1. The solenoids were coupled to the control system and when an open or close instruction was provided, the control system would activate the proper solenoid causing the plunger to move which, in turn, would actuate either the trip device or the close device on the operating mechanism. While the use of linear solenoids is ideal for many conditions in which circuit breakers are used, there are environments where the use of a plunger is detrimental. That is, in situations where the circuit breaker is subjected to shock loads, the mass of the plunger may cause the plunger to move, and therefore actuate the trip/close device, unintentionally. Shock loads, e.g. an impact, may occur where a circuit breaker is located on a vehicle such as, but not limited to, a boat or ship. These shock loads may cause an acceleration up to, or beyond, 300 g, for a very brief period of time. Thus, under a shock load, a plunger having a mass of 100 grams could exert a force of 3 kilograms. This force could be enough to cause the plunger to move as if the solenoid were activated. Thus, the shock load could cause the circuit breaker to trip, or close, accidentally.
There is, therefore, a need for a circuit breaker having a linkage between a solenoid and a trip device and/or a close device, wherein the linkage is ultra-lightweight.
There is a further need for a solenoid for a circuit breaker trip device and/or a close device that is structured to not be actuated under a shock load.